The great thing about the Win Probability Added stat is that it puts a tangible number on big plays and performances with regards to their importance in a game. Obviously, you can feel how big an eighth inning go-ahead hit or stranding the bases loaded in a one-run game is, but with WPA you can put a figure on just how big. It’s fun to know that the Red Sox had a 65 percent change of winning Game 7 of the 2003 ALCS before Jorge Posada’s game-tying double, and that the Yankees than had a 65 percent chance of winning after it.